locore.s revision 54128
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 37 * $FreeBSD: head/sys/i386/i386/locore.s 54128 1999-12-04 13:09:26Z kato $ 38 * 39 * originally from: locore.s, by William F. Jolitz 40 * 41 * Substantially rewritten by David Greenman, Rod Grimes, 42 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 43 * and many others. 44 */ 45 46#include "opt_bootp.h" 47#include "opt_ddb.h" 48#include "opt_nfsroot.h" 49#include "opt_userconfig.h" 50 51#include <sys/syscall.h> 52#include <sys/reboot.h> 53 54#include <machine/asmacros.h> 55#include <machine/cputypes.h> 56#include <machine/psl.h> 57#include <machine/pmap.h> 58#include <machine/specialreg.h> 59 60#include "assym.s" 61 62/* 63 * XXX 64 * 65 * Note: This version greatly munged to avoid various assembler errors 66 * that may be fixed in newer versions of gas. Perhaps newer versions 67 * will have more pleasant appearance. 68 */ 69 70/* 71 * PTmap is recursive pagemap at top of virtual address space. 72 * Within PTmap, the page directory can be found (third indirection). 73 */ 74 .globl _PTmap,_PTD,_PTDpde 75 .set _PTmap,(PTDPTDI << PDRSHIFT) 76 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 77 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 78 79/* 80 * APTmap, APTD is the alternate recursive pagemap. 81 * It's used when modifying another process's page tables. 82 */ 83 .globl _APTmap,_APTD,_APTDpde 84 .set _APTmap,APTDPTDI << PDRSHIFT 85 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 86 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 87 88/* 89 * Globals 90 */ 91 .data 92 ALIGN_DATA /* just to be sure */ 93 94 .globl HIDENAME(tmpstk) 95 .space 0x2000 /* space for tmpstk - temporary stack */ 96HIDENAME(tmpstk): 97 98 .globl _boothowto,_bootdev 99 100 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 101 .globl _cpu_high, _cpu_feature 102 103_cpu: .long 0 /* are we 386, 386sx, or 486 */ 104_cpu_id: .long 0 /* stepping ID */ 105_cpu_high: .long 0 /* highest arg to CPUID */ 106_cpu_feature: .long 0 /* features */ 107_cpu_vendor: .space 20 /* CPU origin code */ 108_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 109 110_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 111physfree: .long 0 /* phys addr of next free page */ 112 113#ifdef SMP 114 .globl _cpu0prvpage 115cpu0pp: .long 0 /* phys addr cpu0 private pg */ 116_cpu0prvpage: .long 0 /* relocated version */ 117 118 .globl _SMPpt 119SMPptpa: .long 0 /* phys addr SMP page table */ 120_SMPpt: .long 0 /* relocated version */ 121#endif /* SMP */ 122 123 .globl _IdlePTD 124_IdlePTD: .long 0 /* phys addr of kernel PTD */ 125 126#ifdef SMP 127 .globl _KPTphys 128#endif 129_KPTphys: .long 0 /* phys addr of kernel page tables */ 130 131 .globl _proc0paddr 132_proc0paddr: .long 0 /* address of proc 0 address space */ 133p0upa: .long 0 /* phys addr of proc0's UPAGES */ 134 135vm86phystk: .long 0 /* PA of vm86/bios stack */ 136 137 .globl _vm86paddr, _vm86pa 138_vm86paddr: .long 0 /* address of vm86 region */ 139_vm86pa: .long 0 /* phys addr of vm86 region */ 140 141#ifdef BDE_DEBUGGER 142 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 143_bdb_exists: .long 0 144#endif 145 146#ifdef PC98 147 .globl _pc98_system_parameter 148_pc98_system_parameter: 149 .space 0x240 150#endif 151 152/********************************************************************** 153 * 154 * Some handy macros 155 * 156 */ 157 158#define R(foo) ((foo)-KERNBASE) 159 160#define ALLOCPAGES(foo) \ 161 movl R(physfree), %esi ; \ 162 movl $((foo)*PAGE_SIZE), %eax ; \ 163 addl %esi, %eax ; \ 164 movl %eax, R(physfree) ; \ 165 movl %esi, %edi ; \ 166 movl $((foo)*PAGE_SIZE),%ecx ; \ 167 xorl %eax,%eax ; \ 168 cld ; \ 169 rep ; \ 170 stosb 171 172/* 173 * fillkpt 174 * eax = page frame address 175 * ebx = index into page table 176 * ecx = how many pages to map 177 * base = base address of page dir/table 178 * prot = protection bits 179 */ 180#define fillkpt(base, prot) \ 181 shll $2,%ebx ; \ 182 addl base,%ebx ; \ 183 orl $PG_V,%eax ; \ 184 orl prot,%eax ; \ 1851: movl %eax,(%ebx) ; \ 186 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 187 addl $4,%ebx ; /* next pte */ \ 188 loop 1b 189 190/* 191 * fillkptphys(prot) 192 * eax = physical address 193 * ecx = how many pages to map 194 * prot = protection bits 195 */ 196#define fillkptphys(prot) \ 197 movl %eax, %ebx ; \ 198 shrl $PAGE_SHIFT, %ebx ; \ 199 fillkpt(R(_KPTphys), prot) 200 201 .text 202/********************************************************************** 203 * 204 * This is where the bootblocks start us, set the ball rolling... 205 * 206 */ 207NON_GPROF_ENTRY(btext) 208 209#ifdef PC98 210 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 211 movl $0xa1400,%esi 212 movl $R(_pc98_system_parameter),%edi 213 movl $0x0240,%ecx 214 cld 215 rep 216 movsb 217#else /* IBM-PC */ 218#ifdef BDE_DEBUGGER 219#ifdef BIOS_STEALS_3K 220 cmpl $0x0375c339,0x95504 221#else 222 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 223#endif 224 jne 1f 225 movb $1,R(_bdb_exists) 2261: 227#endif 228/* Tell the bios to warmboot next time */ 229 movw $0x1234,0x472 230#endif /* PC98 */ 231 232/* Set up a real frame in case the double return in newboot is executed. */ 233 pushl %ebp 234 movl %esp, %ebp 235 236/* Don't trust what the BIOS gives for eflags. */ 237 pushl $PSL_KERNEL 238 popfl 239 240/* 241 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 242 * to set %cs, %ds, %es and %ss. 243 */ 244 mov %ds, %ax 245 mov %ax, %fs 246 mov %ax, %gs 247 248 call recover_bootinfo 249 250/* Get onto a stack that we can trust. */ 251/* 252 * XXX this step is delayed in case recover_bootinfo needs to return via 253 * the old stack, but it need not be, since recover_bootinfo actually 254 * returns via the old frame. 255 */ 256 movl $R(HIDENAME(tmpstk)),%esp 257 258#ifdef PC98 259 /* pc98_machine_type & M_EPSON_PC98 */ 260 testb $0x02,R(_pc98_system_parameter)+220 261 jz 3f 262 /* epson_machine_id <= 0x0b */ 263 cmpb $0x0b,R(_pc98_system_parameter)+224 264 ja 3f 265 266 /* count up memory */ 267 movl $0x100000,%eax /* next, talley remaining memory */ 268 movl $0xFFF-0x100,%ecx 2691: movl 0(%eax),%ebx /* save location to check */ 270 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 271 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 272 jne 2f 273 movl %ebx,0(%eax) /* restore memory */ 274 addl $PAGE_SIZE,%eax 275 loop 1b 2762: subl $0x100000,%eax 277 shrl $17,%eax 278 movb %al,R(_pc98_system_parameter)+1 2793: 280#endif 281 282 call identify_cpu 283 284/* clear bss */ 285/* 286 * XXX this should be done a little earlier. 287 * 288 * XXX we don't check that there is memory for our bss and page tables 289 * before using it. 290 * 291 * XXX the boot program somewhat bogusly clears the bss. We still have 292 * to do it in case we were unzipped by kzipboot. Then the boot program 293 * only clears kzipboot's bss. 294 * 295 * XXX the gdt and idt are still somewhere in the boot program. We 296 * depend on the convention that the boot program is below 1MB and we 297 * are above 1MB to keep the gdt and idt away from the bss and page 298 * tables. The idt is only used if BDE_DEBUGGER is enabled. 299 */ 300 movl $R(_end),%ecx 301 movl $R(_edata),%edi 302 subl %edi,%ecx 303 xorl %eax,%eax 304 cld 305 rep 306 stosb 307 308 call create_pagetables 309 310/* 311 * If the CPU has support for VME, turn it on. 312 */ 313 testl $CPUID_VME, R(_cpu_feature) 314 jz 1f 315 movl %cr4, %eax 316 orl $CR4_VME, %eax 317 movl %eax, %cr4 3181: 319 320#ifdef BDE_DEBUGGER 321/* 322 * Adjust as much as possible for paging before enabling paging so that the 323 * adjustments can be traced. 324 */ 325 call bdb_prepare_paging 326#endif 327 328/* Now enable paging */ 329 movl R(_IdlePTD), %eax 330 movl %eax,%cr3 /* load ptd addr into mmu */ 331 movl %cr0,%eax /* get control word */ 332 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 333 movl %eax,%cr0 /* and let's page NOW! */ 334 335#ifdef BDE_DEBUGGER 336/* 337 * Complete the adjustments for paging so that we can keep tracing through 338 * initi386() after the low (physical) addresses for the gdt and idt become 339 * invalid. 340 */ 341 call bdb_commit_paging 342#endif 343 344 pushl $begin /* jump to high virtualized address */ 345 ret 346 347/* now running relocated at KERNBASE where the system is linked to run */ 348begin: 349 /* set up bootstrap stack */ 350 movl _proc0paddr,%esp /* location of in-kernel pages */ 351 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 352 xorl %eax,%eax /* mark end of frames */ 353 movl %eax,%ebp 354 movl _proc0paddr,%eax 355 movl _IdlePTD, %esi 356 movl %esi,PCB_CR3(%eax) 357 358 movl physfree, %esi 359 pushl %esi /* value of first for init386(first) */ 360 call _init386 /* wire 386 chip for unix operation */ 361 popl %esi 362 363 .globl __ucodesel,__udatasel 364 365 pushl $0 /* unused */ 366 pushl __udatasel /* ss */ 367 pushl $0 /* esp - filled in by execve() */ 368 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 369 pushl __ucodesel /* cs */ 370 pushl $0 /* eip - filled in by execve() */ 371 subl $(13*4),%esp /* space for rest of registers */ 372 373 pushl %esp /* call main with frame pointer */ 374 call _mi_startup /* autoconfiguration, mountroot etc */ 375 376 hlt /* never returns to here */ 377 378/* 379 * When starting init, call this to configure the process for user 380 * mode. This will be inherited by other processes. 381 */ 382NON_GPROF_ENTRY(prepare_usermode) 383 /* 384 * Now we've run main() and determined what cpu-type we are, we can 385 * enable write protection and alignment checking on i486 cpus and 386 * above. 387 */ 388#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 389 cmpl $CPUCLASS_386,_cpu_class 390 je 1f 391 movl %cr0,%eax /* get control word */ 392 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 393 movl %eax,%cr0 /* and do it */ 3941: 395#endif 396 /* 397 * on return from main(), we are process 1 398 * set up address space and stack so that we can 'return' to user mode 399 */ 400 movl __ucodesel,%eax 401 movl __udatasel,%ecx 402 403#if 0 /* ds/es/fs are in trap frame */ 404 movl %cx,%ds 405 movl %cx,%es 406 movl %cx,%fs 407#endif 408 movl %cx,%gs /* and ds to gs */ 409 ret /* goto user! */ 410 411 412/* 413 * Signal trampoline, copied to top of user stack 414 */ 415NON_GPROF_ENTRY(sigcode) 416 call SIGF_HANDLER(%esp) /* call signal handler */ 417 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 418 pushl %eax 419 testl $PSL_VM,UC_EFLAGS(%eax) 420 jne 9f 421 movl UC_GS(%eax),%gs /* restore %gs */ 4229: 423 movl $SYS_sigreturn,%eax 424 pushl %eax /* junk to fake return addr. */ 425 int $0x80 /* enter kernel with args */ 4260: jmp 0b 427 428 ALIGN_TEXT 429_osigcode: 430 call SIGF_HANDLER(%esp) /* call signal handler */ 431 lea SIGF_SC(%esp),%eax /* get sigcontext */ 432 pushl %eax 433 testl $PSL_VM,SC_PS(%eax) 434 jne 9f 435 movl SC_GS(%eax),%gs /* restore %gs */ 4369: 437 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 438 movl $SYS_sigreturn,%eax 439 pushl %eax /* junk to fake return addr. */ 440 int $0x80 /* enter kernel with args */ 4410: jmp 0b 442 443 ALIGN_TEXT 444_esigcode: 445 446 .data 447 .globl _szsigcode, _szosigcode 448_szsigcode: 449 .long _esigcode-_sigcode 450_szosigcode: 451 .long _esigcode-_osigcode 452 .text 453 454/********************************************************************** 455 * 456 * Recover the bootinfo passed to us from the boot program 457 * 458 */ 459recover_bootinfo: 460 /* 461 * This code is called in different ways depending on what loaded 462 * and started the kernel. This is used to detect how we get the 463 * arguments from the other code and what we do with them. 464 * 465 * Old disk boot blocks: 466 * (*btext)(howto, bootdev, cyloffset, esym); 467 * [return address == 0, and can NOT be returned to] 468 * [cyloffset was not supported by the FreeBSD boot code 469 * and always passed in as 0] 470 * [esym is also known as total in the boot code, and 471 * was never properly supported by the FreeBSD boot code] 472 * 473 * Old diskless netboot code: 474 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 475 * [return address != 0, and can NOT be returned to] 476 * If we are being booted by this code it will NOT work, 477 * so we are just going to halt if we find this case. 478 * 479 * New uniform boot code: 480 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 481 * [return address != 0, and can be returned to] 482 * 483 * There may seem to be a lot of wasted arguments in here, but 484 * that is so the newer boot code can still load very old kernels 485 * and old boot code can load new kernels. 486 */ 487 488 /* 489 * The old style disk boot blocks fake a frame on the stack and 490 * did an lret to get here. The frame on the stack has a return 491 * address of 0. 492 */ 493 cmpl $0,4(%ebp) 494 je olddiskboot 495 496 /* 497 * We have some form of return address, so this is either the 498 * old diskless netboot code, or the new uniform code. That can 499 * be detected by looking at the 5th argument, if it is 0 500 * we are being booted by the new uniform boot code. 501 */ 502 cmpl $0,24(%ebp) 503 je newboot 504 505 /* 506 * Seems we have been loaded by the old diskless boot code, we 507 * don't stand a chance of running as the diskless structure 508 * changed considerably between the two, so just halt. 509 */ 510 hlt 511 512 /* 513 * We have been loaded by the new uniform boot code. 514 * Let's check the bootinfo version, and if we do not understand 515 * it we return to the loader with a status of 1 to indicate this error 516 */ 517newboot: 518 movl 28(%ebp),%ebx /* &bootinfo.version */ 519 movl BI_VERSION(%ebx),%eax 520 cmpl $1,%eax /* We only understand version 1 */ 521 je 1f 522 movl $1,%eax /* Return status */ 523 leave 524 /* 525 * XXX this returns to our caller's caller (as is required) since 526 * we didn't set up a frame and our caller did. 527 */ 528 ret 529 5301: 531 /* 532 * If we have a kernelname copy it in 533 */ 534 movl BI_KERNELNAME(%ebx),%esi 535 cmpl $0,%esi 536 je 2f /* No kernelname */ 537 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 538 movl $R(_kernelname),%edi 539 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 540 je 1f 541 movb $'/',(%edi) 542 incl %edi 543 decl %ecx 5441: 545 cld 546 rep 547 movsb 548 5492: 550 /* 551 * Determine the size of the boot loader's copy of the bootinfo 552 * struct. This is impossible to do properly because old versions 553 * of the struct don't contain a size field and there are 2 old 554 * versions with the same version number. 555 */ 556 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 557 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 558 je got_bi_size /* no, sizeless version */ 559 movl BI_SIZE(%ebx),%ecx 560got_bi_size: 561 562 /* 563 * Copy the common part of the bootinfo struct 564 */ 565 movl %ebx,%esi 566 movl $R(_bootinfo),%edi 567 cmpl $BOOTINFO_SIZE,%ecx 568 jbe got_common_bi_size 569 movl $BOOTINFO_SIZE,%ecx 570got_common_bi_size: 571 cld 572 rep 573 movsb 574 575#ifdef NFS_ROOT 576#ifndef BOOTP_NFSV3 577 /* 578 * If we have a nfs_diskless structure copy it in 579 */ 580 movl BI_NFS_DISKLESS(%ebx),%esi 581 cmpl $0,%esi 582 je olddiskboot 583 movl $R(_nfs_diskless),%edi 584 movl $NFSDISKLESS_SIZE,%ecx 585 cld 586 rep 587 movsb 588 movl $R(_nfs_diskless_valid),%edi 589 movl $1,(%edi) 590#endif 591#endif 592 593 /* 594 * The old style disk boot. 595 * (*btext)(howto, bootdev, cyloffset, esym); 596 * Note that the newer boot code just falls into here to pick 597 * up howto and bootdev, cyloffset and esym are no longer used 598 */ 599olddiskboot: 600 movl 8(%ebp),%eax 601 movl %eax,R(_boothowto) 602 movl 12(%ebp),%eax 603 movl %eax,R(_bootdev) 604 605 ret 606 607 608/********************************************************************** 609 * 610 * Identify the CPU and initialize anything special about it 611 * 612 */ 613identify_cpu: 614 615 /* Try to toggle alignment check flag; does not exist on 386. */ 616 pushfl 617 popl %eax 618 movl %eax,%ecx 619 orl $PSL_AC,%eax 620 pushl %eax 621 popfl 622 pushfl 623 popl %eax 624 xorl %ecx,%eax 625 andl $PSL_AC,%eax 626 pushl %ecx 627 popfl 628 629 testl %eax,%eax 630 jnz try486 631 632 /* NexGen CPU does not have aligment check flag. */ 633 pushfl 634 movl $0x5555, %eax 635 xorl %edx, %edx 636 movl $2, %ecx 637 clc 638 divl %ecx 639 jz trynexgen 640 popfl 641 movl $CPU_386,R(_cpu) 642 jmp 3f 643 644trynexgen: 645 popfl 646 movl $CPU_NX586,R(_cpu) 647 movl $0x4778654e,R(_cpu_vendor) # store vendor string 648 movl $0x72446e65,R(_cpu_vendor+4) 649 movl $0x6e657669,R(_cpu_vendor+8) 650 movl $0,R(_cpu_vendor+12) 651 jmp 3f 652 653try486: /* Try to toggle identification flag; does not exist on early 486s. */ 654 pushfl 655 popl %eax 656 movl %eax,%ecx 657 xorl $PSL_ID,%eax 658 pushl %eax 659 popfl 660 pushfl 661 popl %eax 662 xorl %ecx,%eax 663 andl $PSL_ID,%eax 664 pushl %ecx 665 popfl 666 667 testl %eax,%eax 668 jnz trycpuid 669 movl $CPU_486,R(_cpu) 670 671 /* 672 * Check Cyrix CPU 673 * Cyrix CPUs do not change the undefined flags following 674 * execution of the divide instruction which divides 5 by 2. 675 * 676 * Note: CPUID is enabled on M2, so it passes another way. 677 */ 678 pushfl 679 movl $0x5555, %eax 680 xorl %edx, %edx 681 movl $2, %ecx 682 clc 683 divl %ecx 684 jnc trycyrix 685 popfl 686 jmp 3f /* You may use Intel CPU. */ 687 688trycyrix: 689 popfl 690 /* 691 * IBM Bluelighting CPU also doesn't change the undefined flags. 692 * Because IBM doesn't disclose the information for Bluelighting 693 * CPU, we couldn't distinguish it from Cyrix's (including IBM 694 * brand of Cyrix CPUs). 695 */ 696 movl $0x69727943,R(_cpu_vendor) # store vendor string 697 movl $0x736e4978,R(_cpu_vendor+4) 698 movl $0x64616574,R(_cpu_vendor+8) 699 jmp 3f 700 701trycpuid: /* Use the `cpuid' instruction. */ 702 xorl %eax,%eax 703 .byte 0x0f,0xa2 # cpuid 0 704 movl %eax,R(_cpu_high) # highest capability 705 movl %ebx,R(_cpu_vendor) # store vendor string 706 movl %edx,R(_cpu_vendor+4) 707 movl %ecx,R(_cpu_vendor+8) 708 movb $0,R(_cpu_vendor+12) 709 710 movl $1,%eax 711 .byte 0x0f,0xa2 # cpuid 1 712 movl %eax,R(_cpu_id) # store cpu_id 713 movl %edx,R(_cpu_feature) # store cpu_feature 714 rorl $8,%eax # extract family type 715 andl $15,%eax 716 cmpl $5,%eax 717 jae 1f 718 719 /* less than Pentium; must be 486 */ 720 movl $CPU_486,R(_cpu) 721 jmp 3f 7221: 723 /* a Pentium? */ 724 cmpl $5,%eax 725 jne 2f 726 movl $CPU_586,R(_cpu) 727 jmp 3f 7282: 729 /* Greater than Pentium...call it a Pentium Pro */ 730 movl $CPU_686,R(_cpu) 7313: 732 ret 733 734 735/********************************************************************** 736 * 737 * Create the first page directory and its page tables. 738 * 739 */ 740 741create_pagetables: 742 743 testl $CPUID_PGE, R(_cpu_feature) 744 jz 1f 745 movl %cr4, %eax 746 orl $CR4_PGE, %eax 747 movl %eax, %cr4 7481: 749 750/* Find end of kernel image (rounded up to a page boundary). */ 751 movl $R(_end),%esi 752 753/* include symbols if loaded and useful */ 754#ifdef DDB 755 movl R(_bootinfo+BI_ESYMTAB),%edi 756 testl %edi,%edi 757 je over_symalloc 758 movl %edi,%esi 759 movl $KERNBASE,%edi 760 addl %edi,R(_bootinfo+BI_SYMTAB) 761 addl %edi,R(_bootinfo+BI_ESYMTAB) 762over_symalloc: 763#endif 764 765/* If we are told where the end of the kernel space is, believe it. */ 766 movl R(_bootinfo+BI_KERNEND),%edi 767 testl %edi,%edi 768 je no_kernend 769 movl %edi,%esi 770no_kernend: 771 772 addl $PAGE_MASK,%esi 773 andl $~PAGE_MASK,%esi 774 movl %esi,R(_KERNend) /* save end of kernel */ 775 movl %esi,R(physfree) /* next free page is at end of kernel */ 776 777/* Allocate Kernel Page Tables */ 778 ALLOCPAGES(NKPT) 779 movl %esi,R(_KPTphys) 780 781/* Allocate Page Table Directory */ 782 ALLOCPAGES(1) 783 movl %esi,R(_IdlePTD) 784 785/* Allocate UPAGES */ 786 ALLOCPAGES(UPAGES) 787 movl %esi,R(p0upa) 788 addl $KERNBASE, %esi 789 movl %esi, R(_proc0paddr) 790 791 ALLOCPAGES(1) /* vm86/bios stack */ 792 movl %esi,R(vm86phystk) 793 794 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 795 movl %esi,R(_vm86pa) 796 addl $KERNBASE, %esi 797 movl %esi, R(_vm86paddr) 798 799#ifdef SMP 800/* Allocate cpu0's private data page */ 801 ALLOCPAGES(1) 802 movl %esi,R(cpu0pp) 803 addl $KERNBASE, %esi 804 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 805 806/* Allocate SMP page table page */ 807 ALLOCPAGES(1) 808 movl %esi,R(SMPptpa) 809 addl $KERNBASE, %esi 810 movl %esi, R(_SMPpt) /* relocated to KVM space */ 811#endif /* SMP */ 812 813/* Map read-only from zero to the end of the kernel text section */ 814 xorl %eax, %eax 815#ifdef BDE_DEBUGGER 816/* If the debugger is present, actually map everything read-write. */ 817 cmpl $0,R(_bdb_exists) 818 jne map_read_write 819#endif 820 xorl %edx,%edx 821 822#if !defined(SMP) 823 testl $CPUID_PGE, R(_cpu_feature) 824 jz 2f 825 orl $PG_G,%edx 826#endif 827 8282: movl $R(_etext),%ecx 829 addl $PAGE_MASK,%ecx 830 shrl $PAGE_SHIFT,%ecx 831 fillkptphys(%edx) 832 833/* Map read-write, data, bss and symbols */ 834 movl $R(_etext),%eax 835 addl $PAGE_MASK, %eax 836 andl $~PAGE_MASK, %eax 837map_read_write: 838 movl $PG_RW,%edx 839#if !defined(SMP) 840 testl $CPUID_PGE, R(_cpu_feature) 841 jz 1f 842 orl $PG_G,%edx 843#endif 844 8451: movl R(_KERNend),%ecx 846 subl %eax,%ecx 847 shrl $PAGE_SHIFT,%ecx 848 fillkptphys(%edx) 849 850/* Map page directory. */ 851 movl R(_IdlePTD), %eax 852 movl $1, %ecx 853 fillkptphys($PG_RW) 854 855/* Map proc0's UPAGES in the physical way ... */ 856 movl R(p0upa), %eax 857 movl $UPAGES, %ecx 858 fillkptphys($PG_RW) 859 860/* Map ISA hole */ 861 movl $ISA_HOLE_START, %eax 862 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 863 fillkptphys($PG_RW) 864 865/* Map space for the vm86 region */ 866 movl R(vm86phystk), %eax 867 movl $4, %ecx 868 fillkptphys($PG_RW) 869 870/* Map page 0 into the vm86 page table */ 871 movl $0, %eax 872 movl $0, %ebx 873 movl $1, %ecx 874 fillkpt(R(_vm86pa), $PG_RW|PG_U) 875 876/* ...likewise for the ISA hole */ 877 movl $ISA_HOLE_START, %eax 878 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 879 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 880 fillkpt(R(_vm86pa), $PG_RW|PG_U) 881 882#ifdef SMP 883/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 884 movl R(cpu0pp), %eax 885 movl $1, %ecx 886 fillkptphys($PG_RW) 887 888/* Map SMP page table page into global kmem FWIW */ 889 movl R(SMPptpa), %eax 890 movl $1, %ecx 891 fillkptphys($PG_RW) 892 893/* Map the private page into the SMP page table */ 894 movl R(cpu0pp), %eax 895 movl $0, %ebx /* pte offset = 0 */ 896 movl $1, %ecx /* one private page coming right up */ 897 fillkpt(R(SMPptpa), $PG_RW) 898 899/* ... and put the page table table in the pde. */ 900 movl R(SMPptpa), %eax 901 movl $MPPTDI, %ebx 902 movl $1, %ecx 903 fillkpt(R(_IdlePTD), $PG_RW) 904 905/* Fakeup VA for the local apic to allow early traps. */ 906 ALLOCPAGES(1) 907 movl %esi, %eax 908 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 909 movl $1, %ecx /* one private pt coming right up */ 910 fillkpt(R(SMPptpa), $PG_RW) 911 912/* Initialize mp lock to allow early traps */ 913 movl $1, R(_mp_lock) 914#endif /* SMP */ 915 916/* install a pde for temporary double map of bottom of VA */ 917 movl R(_KPTphys), %eax 918 xorl %ebx, %ebx 919 movl $1, %ecx 920 fillkpt(R(_IdlePTD), $PG_RW) 921 922/* install pde's for pt's */ 923 movl R(_KPTphys), %eax 924 movl $KPTDI, %ebx 925 movl $NKPT, %ecx 926 fillkpt(R(_IdlePTD), $PG_RW) 927 928/* install a pde recursively mapping page directory as a page table */ 929 movl R(_IdlePTD), %eax 930 movl $PTDPTDI, %ebx 931 movl $1,%ecx 932 fillkpt(R(_IdlePTD), $PG_RW) 933 934 ret 935 936#ifdef BDE_DEBUGGER 937bdb_prepare_paging: 938 cmpl $0,R(_bdb_exists) 939 je bdb_prepare_paging_exit 940 941 subl $6,%esp 942 943 /* 944 * Copy and convert debugger entries from the bootstrap gdt and idt 945 * to the kernel gdt and idt. Everything is still in low memory. 946 * Tracing continues to work after paging is enabled because the 947 * low memory addresses remain valid until everything is relocated. 948 * However, tracing through the setidt() that initializes the trace 949 * trap will crash. 950 */ 951 sgdt (%esp) 952 movl 2(%esp),%esi /* base address of bootstrap gdt */ 953 movl $R(_gdt),%edi 954 movl %edi,2(%esp) /* prepare to load kernel gdt */ 955 movl $8*18/4,%ecx 956 cld 957 rep /* copy gdt */ 958 movsl 959 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 960 movb $0x92,-8+5(%edi) 961 lgdt (%esp) 962 963 sidt (%esp) 964 movl 2(%esp),%esi /* base address of current idt */ 965 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 966 movw 8(%esi),%ax 967 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 968 movl 8+2(%esi),%eax 969 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 970 movl 24+4(%esi),%eax /* same for bpt descriptor */ 971 movw 24(%esi),%ax 972 movl %eax,R(bdb_bpt_ljmp+1) 973 movl 24+2(%esi),%eax 974 movw %ax,R(bdb_bpt_ljmp+5) 975 movl R(_idt),%edi 976 movl %edi,2(%esp) /* prepare to load kernel idt */ 977 movl $8*4/4,%ecx 978 cld 979 rep /* copy idt */ 980 movsl 981 lidt (%esp) 982 983 addl $6,%esp 984 985bdb_prepare_paging_exit: 986 ret 987 988/* Relocate debugger gdt entries and gdt and idt pointers. */ 989bdb_commit_paging: 990 cmpl $0,_bdb_exists 991 je bdb_commit_paging_exit 992 993 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 994 movl $9,%ecx 995reloc_gdt: 996 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 997 addl $8,%eax /* now KERNBASE>>24 */ 998 loop reloc_gdt 999 1000 subl $6,%esp 1001 sgdt (%esp) 1002 addl $KERNBASE,2(%esp) 1003 lgdt (%esp) 1004 sidt (%esp) 1005 addl $KERNBASE,2(%esp) 1006 lidt (%esp) 1007 addl $6,%esp 1008 1009 int $3 1010 1011bdb_commit_paging_exit: 1012 ret 1013 1014#endif /* BDE_DEBUGGER */ 1015